JPS5927457B2 - Clutch/brake unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch used as a clutch and a brake, of the type that uses a coil spring to transmit torque between the drive surfaces of an input hub and an output hub attached to a rotating shaft. It relates to a unit that combines a brake, that is, a clutch/brake unit. In particular, the input hub is fixed to a shaft, the output hub is bearing on the shaft, and a coil spring is arranged between these two hubs. In the normal state where the coil spring has one turn, the coil spring has two turns.
It engages the drive faces of the two bubs so that torque is transmitted between the drive faces of the two bubs, so that the output hub rotates with the input hub, and when the brakes are applied, the coil spring is unwound. The present invention relates to a clutch/brake unit that separates the connection between the two brake members and transmits braking torque from the brake member to the output hub.

Specification of "Clutch Brake Assembly" (% Publication No. 58-1060 filed by the applicant on August 26, 1975)
In the latch brake assembly as described in Publication No. 4), the sleeve fixed to the output hub covers the spring and is placed away from the spring, and the brake member moves slightly in the axial direction. It is supported in the assembly so as to move toward and away from the input end of the spring.

In this clutch brake assembly, when the clutch is released and the brake is applied, the yoke slides and frictionally engages the brake member, thereby sliding the brake member axially inward and engaging the input end of the spring. As a result, the brake member and the output surface rotate relative to each other, the spring is unwound, and the engagement between the spring and the input/output surface is loosened.
The clutch of the assembly is disengaged and the spring is used to transmit braking torque from the brake member to the output.

However, with the above assembly, when the assembly is applied to a lawn garden tractor, for example, when the assembly is operated in dense, tall weeds, weeds accumulate in the movable parts of the tractor, causing the cutter to stop moving. If the motor that drives the output is overloaded and a static load is applied to it, causing it to stop moving,
Since the input and output pins are stopped with a static load applied to their shafts, even if the yoke is moved and makes contact with the brake member, no relative movement will occur between the brake member and the output pin. Since there is no spring, the spring is not unwound and therefore the assembly cannot be easily declutched.

As a result, when an attempt is made to restart a motor that has stopped under a static load, the coil spring will
The coil spring remains wrapped around the spring and output, and the coil spring remains connected, so unless you remove this load or remove the clutch before starting the motor, the coil spring will burn out. Otherwise, it had the disadvantage of becoming extremely weak.

The main object of the present invention is to eliminate the above-mentioned drawbacks, provide a feature of actively disengaging the clutch in conjunction with braking, regardless of whether a static load or an opposite load is acting, and provide a lawn garden To provide a clutch/brake unit that can be used even under relatively large loads that occur during normal operation of a tractor, etc., such as when mowing tall dense weeds with a cutter. There is something to do.

To achieve this object, the invention provides, in particular, a novel coupling device between the brake member and the sleeve, which allows for relative rotation of the brake disc, i.e. the follower device 40 of the brake disc.
The sleeve is also provided with a guide 39 and the input end 31 of the spring is brought into engagement with the coupling device to rotate the brake member relative to the sleeve by sliding the brake member inwardly by means of the yoke. At the same time, the input end of the spring is forcibly driven in the unwinding direction, and even if a static load is applied to the unit and the motor is stopped, the spring can be actively unwound and moved away from the input hub. The feature is that the clutch action of the output surface bubble is released.

Further embodiments of the invention provide for adjusting the angular position of the slot with respect to the input end of the spring so that one side of the A novel construction device is provided for attaching the sleeve to the input cup such that the input end of the spring is received in the slot.

Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 and 2 are side views of the first embodiment (Figure 2 shows the brake disc in a moved state); mounted on the rotating shaft, and therefore the rotating shaft 1 of the same unit.
5 is driven by the motor of the tractor and has the same output.
Therefore, it is connected to the sheave 21 via a rope or belt so as to drive the driven equipment of the tractor (not shown), such as a rotary lawn mower blade.

As shown in the figure, input...B 13 and output...B 14
are both co-cylindrical and have drive faces 19,20 on the outside, which drive faces 19,20 are radially equidistant from the central axis of the shaft 15.

The diameter of the spring 11 in its natural state is smaller than the diameter of the drive surface, so that the spring frictionally engages the drive surface to form a torque-transmitting connection between the two bars.

A large sheave 21, adapted to be drivingly connected to the tractor driven equipment (not shown) as described above, is integrally formed with the output tube 14 and surrounds the bearing 16.

A cylindrical sleeve 23 with an inner surface 24 projects radially from the sheave towards the input section, the inner surface 24 departing radially outwardly from the drive surface 19,20 of the section so that the clutch of the unit 10 When disengaged, the spring unwinds leaving a chamber that separates outward from the drive surface.

The sleeve is secured to an annular flange 26 formed integrally with one end 2γ of the sleeve and extending radially outwardly therefrom by means of four screws 25 (see FIG. 3).

A disc-shaped brake member 30 is slidably attached to the opposite or free end 29 (see FIGS. 2 and 4) of the sleeve.

The brake member 30 is connected to the input end of the spring when applying a brake torque to the disc, and unwinds the spring to release the bub 13,
14 drive surface 19.20.

The disc 30 has a cylindrical central portion 31 overlying the free end portion of the sleeve 23, the inner end of which is also spaced axially inwardly from the free end 29 of the sleeve.

An annular flange 3 integrally formed with the inner end of the central portion
3 extends radially outward from the central portion and forms an outer braking surface 34 on which a Y-shaped brake shoe 35 engages.

Brake shoes 35 are mounted on the tractor and can be moved into and out of engagement with the disc by manipulating a tow cable (not shown).

In the normal driving state of the unit, the bubs 13 and 14 rotate together, but when the brake is applied, the brake shoes are moved in the direction of arrow #]A (see Figure 1) and engage the disc. and move the disc axially inward (to the right in the figure), i.e. 2
axially against the two bubs to transmit braking torque to the output hub.

Two diametrically opposed wear pads 36 on the brake shoes frictionally engage the outer surface 34 of the disc to decelerate the disc as it rotates with shaft 15, and furthermore, the disc and output hub are Since they are connected to transmit torque, they decelerate the output that rotates with the shaft.

At the same time, the connection between the disk and the free end of the spring (left end in the figure)
The input and output ends of the spring rotate relative to each other to unwind the spring away from the drive surface 19.20, thereby unclutching the assembly.

The above points are almost the same as those of the prior art.

However, in this invention, in particular, the brake member or disc 30
A new coupling device is provided between the sleeve 23 and the spring 11, which allows the unit to actively maintain its position even when braking the unit under static load. The arrangement is such that failure of the unit when the clutch is disengaged and thus restarts the engine can be actively avoided.

Thus, in this embodiment, the guide and follower device includes a number of helical slots 39 (see FIG. 4) formed in the free end portion 29 of the sleeve 23 and integrally formed with the disc 30 and extending into the slots. It consists of the same number of protrusions 40.

The tongues extending radially outward from the point integrally connected to the input end of the spring are the members 3γ that connect the guide and follower device to the sleeve.

The tongue 3γ enters the slot and is caught between the inner end 41 of the slot and the protrusion entering the slot.

The tongues are preferably pressed elastically against the projections, so that when the disc is slid axially inwardly on the sleeve with the brake shoe 35, the tongues are pushed along the slots and are pressed against the output end of the spring. The input end of the spring is rotated against it, so that the spring is unwound and away from the drive surface of the input hub 13 and the unit 10 is positively declutched.

As shown in particular in FIG. 4, three slots 39 are formed in the free end portion 29 of the sleeve 23, and the slots are spaced equiangularly apart from each other around the sleeve.

Additionally, each slot is formed in the side of the sleeve with its outer end opening axially from the free end of the sleeve.

The slots run parallel to each other towards the fixed end 2γ of the sleeve and are inclined in a direction opposite to the normal direction of rotation of the axis 150.

As a result, the inner ends 41 of each slot are circumferentially spaced behind the outer (free) ends of the slots with respect to the normal direction of rotation of the shaft.

Three prongs 40 are integrally formed on the outer end of the central portion 31 of the brake disc 30 and extend radially inwardly from there into the slots 39 .

Each lug extends diagonally through its respective slot because the rotationally leading end portion 38 of the lug is bent axially outwardly from the sleeve and parallel to the sides 44 of the slot.

In somewhat the same way, the rotationally lagging end portion 4 of each lug
2 is bent inwards parallel to the side surface 45 of the slot near this end section.

Each protrusion is therefore S-shaped and extends diagonally across the respective slot and engages the sides of the slot on both sides.

As shown in FIGS. 1 and 2, a cylindrical dust-proof cover 46 attached to the shaft 15 is located near the outer end 4γ of the input hub 13 to prevent the protrusion 40 from sliding out of the slot 39 in the axial direction. Make it.

The tubular wall of this cover concentrically overlies the central portion 31 of the disc 30.

A radial wall 50 integrally formed at the axially outer end of the tubular wall extends radially inwardly along the outer end of the input hub and abuts the shaft.

The spacing between the radial inner surface 51 and the free end 29 of the sleeve 23 is less than the axial distance between the ends 38.42 of the lug, so that the lug is retained in the slot and allows the disc to rotate with the sleeve. to hold.

Because the helical slot is inclined, the rotational force of the sleeve during driving of the unit 10 forces the prongs inwardly along the slot and out of frictional contact with the inner surface 51 of the radial wall 500.

In practicing the invention, the axially expanding rings 53 (first and fourth (see figure) is formed at the input end portion of the spring.

When this winding expands, the tongue piece 3r is pushed away from the inner end 41 in the slot 39 and engages with a projection piece 40 in the slot.

When the disc is slid inward by the brake yoke 35, the winding contracts (see Figure 2) and the input tongue moves along the slot so that the input end of the spring is relative to its output end. The spring unwinds away from the input hub and the unit is declutched, whether or not the unit is under a static load.

When the winding ring is sufficiently contracted and the input tab contacts the inner end of the slot, the disc connects to the sleeve 23 and together with the output tab 14 forms a friction brake to stop.

In order to avoid frictional contact between the input end portion of the spring 11 and the input section 13 when the winding ring 53 contracts in the axial direction, the inner surface of the input end section of the spring, including the expanded winding ring, is connected to the input end section of the input section 13. radially outward away from the drive surface.

In an exemplary embodiment of the invention, this spacing places the input end of the spring on an axially outer side with a relaxed diameter greater than the diameter of the drive face of the input hub, although this may be accomplished with other constructions. This is achieved by constructing it with two winding rings.

Therefore, the axially expanding winding ring of the spring can move freely in the axial direction without engaging the drive surface of the input tube.

According to this embodiment constructed as described above, the guide or helical slot 39 and the follower device or lug 4 formed in the sleeve 23 and the brake disc 30 respectively
0 is working together to brake the brake disc 30 with the sleeve 23.
When rotated relative to ...Remove from Bu 13.

This structure allows the unit to be actively disengaged during braking, even when a static load is applied to the unit.

Therefore, even if the tractor motor is restarted, the clutch/brake unit will not fail.

This failure occurs when an attempt is made to start the motor with the springs attached to the input and output pins and a static load being applied.

Further, when assembling the clutch/brake unit 10 of the present invention, the relative angular positions of the output tongue 1γ and the input tongue 3γ of the spring 11 are determined by the diameter of the spring and the input and output hub 13.
．． It can be seen that the diameter of 14 is always different from unit to unit due to variations in tolerance.

For this reason, this invention has a sleeve 2 for the output tongue 1γ.
The angular position of the slot 40 that receives the tongues 3 of 3 is adjusted to eliminate distortion of the input tongues 31 that would cause the springs to frictionally engage the drive surfaces 19, 20 of the input and output tabs 13 and 14. ing.

For this purpose, the output tongue piece 11 is fixed at the fixed end 2 of I)-7'.
It is fitted into a tongue notch 54 formed in the sheave 21 close to γ and is held in the notch by the seven flange 26 of the sleeve so as not to move relative to the output cup.

Further, an arcuate hole 55 formed in the flange 26 is provided with a rivet 5.
6, these rivets extend axially through the two halves of the sheave to hold the sheave and flange together.

The outer end of the rivet becomes a stud which serves to rotationally adjust the position of the slot 39 relative to the output tongue to guide the sleeve concentrically into the input and output tongues.

Therefore, when installing the sleeve on the rope shaft, the sleeve is rotated relative to the input end of the spring until one of the slots receives an input tongue 31, in which case such tongue 3γ
is not pushed further from its normal relative angular position with respect to the output tongue 1γ.

Once the sleeve is properly positioned on the rigging, the sleeve is attached to the rigging by tightening the screws to the flange.

Other embodiments of the invention are shown in FIGS.

- In these drawings, parts corresponding to the first embodiment of the invention are indicated by the same reference numerals with a '' added.

In this embodiment, the clutch/brake unit 10'
The sleeve 23' has an outer end portion 57 (see FIG. 5) of each of the helical slots 39' extending axially.

With this construction, the protrusion 40' of the brake disc 30' is pushed into the outer end portion of the slot by the spring tongue 3γ' during normal rotation of the unit.

The brake disc is thus held against sliding along the slot toward the output end of the sleeve when the sleeve is periodically accelerated and rotated at high speed by the power pulses of the motor.

This is because the outer end portion 5γ of the slot is shaped to apply an axial component of the torsional power pulse to the flared end portion 53' of the spring 11.

As a result, the spring is held against unwinding by the brake disc during normal operation of the tractor.

In the clutch/brake unit 10', the spring 11'
In order to adjust the angular position of the tongue receiving slot 39' with respect to the output tongue 1γ' (see FIG. 6), the output tongue 1γ' (see FIG. It extends through an arcuate hole 59 that extends into.

The arcuate holes allow the springs to be frictionally engaged with the input and output cups 13', 14' without unduly straining the spring tongues 1γ', 3γ'.

When the input tongue is placed in one of the slots 39' and the output tongue is placed in the hole 59 and the spring is assembled to the input and output... cylinders with axial slits 61 (FIG. 7) A shaped spring clip 60 is placed within the output hole to hold the output tongue against circumferential movement within the hole.

Because the clip's relaxed diameter is greater than the inner diameter of the output hub, the clip frictionally engages the inner surface 62 of the output hub.

When the clip is inserted into the output hole, the slit is aligned with and receives the output tongue of the spring and holds it stationary within the hole during operation of the clutch/brake unit 10'. do.

When assembling the clutch/brake unit 10' as shown in FIG.
It is installed on the inner bipedal body.

The pin extends axially outwardly from the flange and enters a recess formed in the inner bifurcation of the sheave to guide the sleeve concentrically with the sheave.

It also has a pin 65 on the inside of the sheave, which enters a hole 66 in the outside of the sheave so that the three parts (the pin and the two halves of the sheave) Rivet 56'
The two arm halves of the sheave 02 are guided so as to be concentric with the two arm halves of the sheave, and the two halves of the sheave are connected to each other with rivets.

From the above description, it is clear that the present invention allows the brake disc 30 and the sleeve 2 to be fixed even when a static load is applied to the unit.
3 and spring 11, a new latch system is created that actively disengages the clutch during braking.
It will be seen that the brake unit is brought to this field of technology.

Advantageously, this means that when the disc is moved axially inwardly with the brake yoke 35, the input tongue 37 is pushed along one of the helical slots 39, thereby placing a static load on the unit. This can also be accomplished by attaching a disk to the free end portion of the sleeve, which unwinds the spring away from the input hub, whether or not the input hub is engaged.

It is also possible to provide a helical spring inside the input/output terminals and to expand the springs outward in order to clutch the terminals.

[Brief explanation of drawings]

FIG. 1 shows a clutch embodying the novel features of this invention.
FIG. 2 is a partial cross-sectional view similar to FIG. 1, showing a portion of the clutch/brake unit in a moved position; 3 is a sectional view taken along the line 3-3 in FIG. 1, FIG. 4 is a partial perspective view of the clutch/brake unit of the present invention in an exploded arrangement, and FIG. FIG. 6 is a partial side view of another embodiment of the present invention, and FIG. 6 is a partial side view of FIG.
7 is a cross-sectional view taken along line 1-7 of FIG. 6. FIG. In the figure, 11 is a helical spring, 13 is an input...
4 is the output, 23 is the sleeve, 30 is the brake member, that is, the brake disk, 35 is the brake shoe, 3
7. 39 indicates a number of slots formed in the sleeve; 40 indicates a protrusion provided on the brake disc; Configure the guide and follower devices.

Claims (1)

[Claims] 1 An input hub and an output hub that rotate relative to each other, and a hub that is radially separated from the input hub and the output hub.
a sleeve surrounding the two bubs and having one end free and the other end fixed to said output hub for rotation therewith; a helical spring that engages the two bubs to transmit torque to the spring, and has an input end located near the input hub and an output end fixed to the output hub;
- a brake disc supported on the free end of said sleeve and mounted near said brake disc for engaging said brake disc during braking to cause said disc to slide axially relative to said sleeve; a movable brake shoe and a guide and follower device provided on said sleeve and said brake disc and adapted to rotate said brake disc relative to said sleeve in conjunction with said sliding movement; and an input end of the spring is coupled to the follower device such that when the brake disc rotates relative to the sleeve during braking, the input end of the spring rotates together with the brake disc relative to the sleeve. Clutch/brake unit, characterized in that even when a static load is applied to the unit, the spring is unwound and separated from the input hub to actively disengage the clutch of the unit.